Centering gauge



Oct. 22, 1935. L FREEMAN ET AL 2,@E$,55@

.CENTERING GAUGE Filed Oct. '6, 1933 FrquRE 2 I Patented Oct. 22, 1935 UNITED STATES CENTERING GAUGE Lloyd E. Freeman and Fred V. Clancy, San Jose, Calif.

Application October 6,

2 Claims.

The present invention relates particularly to means for checking the centering and clearances of vehicle-wheel brake-shoe assemblies relative to the drums against which they operate, and also for checking the condition of the drums.

It is one object of the invention to provide a gauge of the character indicated so constructed and operated as to be quickly and accurately ad- Justed to the wearing surface of a brake drum, and one in which the effecting of said adjustment automatically centers the gauge in the said drum.

It is another object of the invention to provide a gauge of the character indicated that may be accurately mounted upon the axle carrying the drum with its axis coinciding with the axis of the axle.

It is still another object of the invention to provide a gauge wherein the setting for the internal diameter of the drum and the external diameter of the brake shoes, and for its centering in the drum, is accomplished in the one adjustment.

Still other objects are to provide a gauge for checking the vertical and horizontal disposition of surfaces relative to a given axis; for taking the internal or external diameters of objects and instantly checking those measurements with the internal or external diameters of other or like objects.

Finally, it is an object of the invention to provide a gauge of the character indicated that will be economical to manufacture, that consists of few parts, that is simple in form and construction, strong, durable, and highly efilcient in its practical application.

In the drawing:

Figure 1 is a plan view of a gauge embodying our invention, partly in section, and with parts broken away.

Figure 2 is a sectional view on line 2-2 of Figure 1, with parts broken away.

In the embodiment of the invention herein disclosed, we show at l a tubular hub open at both ends and having four equally spaced and radially disposed tubular arms mounted thereon, as by welding, to form .an integral part thereof. The longitudinal axes of these arms are all disposed in one plane at right angles to the axis of hub l, the several arms being indicated by the reference characters 2, 2a, 2b, 2c.

It is to be understood that the several arms and the parts mounted therein are identical in every respect, and that the detailed description of one arm applies equally as well to each of the others.

At 3-and I are shown two dead centers dis- 1933, Serial No. 692,489

posed in opposed relation to each other and in axial alignment. The part 3 is mounted on the hub l and within the arm 2, its axis coinciding with that of the said arm, and the part 4 is threaded into a nut 5 removably secured in the 5 outer end of the arm by screws 6.

At 1 is a threaded spindle mounted to rotate in the dead centers 3 and 4. Threaded on to the spindle 1 is a sleeve 8 provided .withoppositely directed arms 9 and ill passing through slots H and i2, respectively, in opposite sides of arm 2. The outer edge l3 of arm or gauge plate 9 is straight and is parallel with the axis of hub I, and the inner edge M of gauge plate in is also a straight-edge and is aligned with edge iii of 15 plate 9. The plate i0 is longer than plate 9 for the purpose hereinafter described.

Revolubly mounted on hub I and held in place by means of a collar i5 and set screws i6, is a bevel gear I! meshing with a pinion l8 on spindle 20 l, and of course with pinions l8w, I8b and we on their respective spindles. An opening I9 is formed in tube or arm 2 to permit the operation of the gear as described.

The oppositely directed spindles 11b and 25 la-lc are provided with right and left threads respectively so that when the gear I! is rotated all of the gauge plates are moved an equal degree in the same direction with respect to the center of the huh I.

Slidably mounted in the hub l is a bearing member 20 formed at 2! to slidably engage the end of a vehicle axle, and tapped at 22 to engage the threaded pin on the end of said axle. At 23 is shown a set-screw mounted in the member 20, 35 its axis of rotation being concentric with the axis 01' the hub, bearing member, and axle.

In using the device for recentering the brake shoes of an automobile wheel the brake drum is removed from the wheel, and the device is laid 00 upon it with the four gauge plates 9, 9a, 9b, 9c within the same. The gear I! is now operated to move all of the said gauge plates outwardly into engagement with the wearing surface of the drum, this operation automatically centering the 45 huh I in the drum. By rotating the device in the drum the condition of the wearing surface, indicated in dotted lines at 24, may be readily ascertained.

When the bearing member 20 is in place on the 50 axle, indicated in part-in dotted lines at 25, the set-screw 23 is operated to seat in the conical indentation, or center, found in the end of each axle end. where sufllcient pressure is brought to bear to exert a pull on the bearing member. This 55 operation seats the threads of the bearingmemrber firmly against the threads of the axle and positively supports the member in true axial alignment with the end portion of the axle upon which it is mounted. This is animportant feature of the. invention because'it is the accurate mounting of the bearing member on the axle that 7 permits accurate application of the device in'the manner described.

The gauge plates having been adjusted as above described, the device is now removed from the drum and slidably mounted upon the bearing member 20 with thegaugepiates IO, 10a,

, lob, 10c overlying the brake shoes, indicated in a part in dotted lines at 26, 2611. Since the working edges'oi these gauge plates are in accurate 7 "alignment with the working edges of the gauge plates 9 to Go, it follows that the brake shoes may be set to these plates and the highestpos- 'sible degreeo! accuracy obtained between their wearing surfaces and that of the drum in which they are mounted.

Since the spindles Tto 1c are disposed at right angles to the axis 01 the huh I, and the several working edges il to He and to He are disposed at right angles to the plane of the spindles, it follows that the positions or the several parts encompassing the device relative to these gauge plates, clearly indicates and quickly disclose: any deviation from the normal.

It is to be understood, of course, that while we 7 prising, a bearing member mountable upon a vehicle axle and having centralizing means associated therewith and adapted to be fixedly mounted on the axle, a hub adapted to slidably engage the bearing member, radially adjustable gauge members associated with the hub, and

. actuating means for the gauge members centralized on the hub.

V 20 2. The combination with a member having a threaded terminal portion provided with an indentation in the center of its end, of an ele merit slidably mounted 'on the member and tapped to receive the threaded terminal portion 25 0! said member, and a set screw engaging the tapped portion 01' the element and disposed'to seat in the said indentation.

' FRED V. CLANCY.

LLOYD E. FREEMAN. 5 

